Over the last few decades, an ever-increasing amount of software has been distributed by commercial software vendors. A great deal of this software has been subject to unauthorized copying, since those software obstacles which have been erected to prevent copying have been circumvented by increasingly sophisticated copying techniques used by consumers or competitors.
There has also been an ever-increasing number of computer systems and databases which can be accessed remotely via telephone, microwave or even satellite links. The security of many of these systems, and often times the integrity of the data stored therein, is subject to compromise or has been compromised by unauthorized persons. Recent reports in the media and trade journals about hackers, embezzlers and others document this growing problem.
The increasing use of electronic equipment by banks and other financial institutions to conduct transactions among themselves and with their customers, such as transferring funds, or sending and receiving other financially sensitive information, has spawned additional computer security problems. Insiders or others with the proper passwords and/or command sequences are able to subvert these electronic funds transfer systems for their own gain, at times without being detected. Sensitive financial information, for example, may be compromised by an unauthorized person who inspects but does not alter the information.
To combat these growing problems, a number of alternative solutions have recently been proposed. The following U.S. Pat. Nos. are examples of the general state of the art regarding solutions for various computer security problems:
4,105,156 PA1 4,120,030 PA1 4,183,085 PA1 4,246,638 PA1 4,377,844 PA1 4,433,207